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Selected AbstractsFour ways towards tropical herbivore megadiversityECOLOGY LETTERS, Issue 4 2008Thomas M. Lewinsohn Abstract Most multicellular species alive are tropical arthropods associated with plants. Hence, the host-specificity of these species, and their diversity at different scales, are keys to understanding the assembly structure of global biodiversity. We present a comprehensive scheme in which tropical herbivore megadiversity can be partitioned into the following components: (A) more host plant species per se, (B) more arthropod species per plant species, (C) higher host specificity of herbivores, or (D) higher species turnover (beta diversity) in the tropics than in the temperate zone. We scrutinize recent studies addressing each component and identify methodological differences among them. We find substantial support for the importance of component A, more tropical host species. A meta-analysis of published results reveals intermediate to high correlations between plant and herbivore diversity, accounting for up to 60% of the variation in insect species richness. Support for other factors is mixed, with studies too scarce and approaches too uneven to allow for quantitative summaries. More research on individual components is unlikely to resolve their relative contribution to overall herbivore diversity. Instead, we call for the adoption of more coherent methods that avoid pitfalls for larger-scale comparisons, for studies assessing different components together rather than singly, and for studies that investigate herbivore beta-diversity (component D) in a more comprehensive perspective. [source] Institutional Structure and Immigrant Integration: A Comparative Study of Immigrants' Labor Market Attainment in Canada and Israel,INTERNATIONAL MIGRATION REVIEW, Issue 2 2003Noah Lewin-Epstein The present study focuses on the incorporation of immigrants from the former Soviet Union in two receiving societies, Israel and Canada, during the first half of the 1990s. Both countries conducted national censuses in 1995 (Israel) and 1996 (Canada), making it possible to identify a large enough sample of immigrants and provide information on their demographic characteristics and their labor market activity. While both Canada and Israel are immigrant societies, their institutional contexts of immigrant reception differ considerably. Israel maintains no economic selection of the Jewish immigrants and provides substantial support for newcomers, who are viewed as a returning Diaspora. Canada employs multiple criteria for selecting immigrants, and the immigrants' social and economic incorporation is patterned primarily by market forces. The analysis first examines the characteristics of immigrants who arrived in the two countries and evaluates the extent of selectivity. Consistent with our hypotheses, Russian immigrants to Canada were more immediately suitable for the labor market, but experienced greater difficulty finding and maintaining employment. Nevertheless, immigrants to Canada attained higher-status occupations and higher earnings than their compatriots in Israel did, although the Israeli labor market was more likely to reward their investments in education. [source] Gender and Negotiation: Some Experimental Findings from an International Negotiation Simulation1INTERNATIONAL STUDIES QUARTERLY, Issue 1 2009Mark A. Boyer Increasingly, scholars have taken note of the tendency for women to conceptualize issues such as security, peace, war, and the use of military force in different ways than their male counterparts. These divergent conceptualizations in turn affect the way women interact with the world around them and make decisions. Moreover, research across a variety of fields suggests that providing women a greater voice in international negotiations may bring a fresh outlook to dispute resolution. Using experimental data collected by the GlobalEd Project, this article provides substantial support for hypotheses positing that females generate significantly different processes and outcomes in a negotiation context. These findings occur both in terms of female negotiation behavior and the impact of females as negotiation facilitators/mediators. [source] Winter selection of landscapes by woodland caribou: behavioural response to geographical gradients in habitat attributesJOURNAL OF APPLIED ECOLOGY, Issue 5 2008Daniel Fortin Summary 1Understanding animal,habitat relationships is central to the development of strategies for wildlife management and conservation. The availability of habitat attributes often changes along latitudinal and longitudinal axes, and animals may respond to those changes by adjusting their selection. We evaluated whether landscape selection by forest-dwelling woodland caribou Rangifer tarandus caribou varied along geographical gradients in habitat attributes. 2Centroids (n = 422) of track networks made by caribou in winter were recorded during aerial surveys conducted over 161 920 km2 of boreal forest in Québec, Canada. Autologistic models were estimated by comparing the characteristics of landscapes (201 km2) centred on each centroid to an equal number of randomly located landscapes, with an autocovariate controlling for the non-independence among caribou locations. 3The availability of habitat attributes varied along longitudinal and latitudinal gradients, and caribou altered their landscape selection with respect to those gradients. 4Information Theory provided substantial support for only one model. The model revealed that the probability of occurrence of caribou increased with the abundance of conifer forests over most of the study region, but this positive response gradually became negative towards the southern portion of the region. The association between caribou and lichens changed from being negative west of the study region to being positive in the eastern part. Availability of landscapes dominated by lichen decreased from west to east. Finally, caribou generally displayed an aversion to areas with high road density, a negative association that became positive in the southern part of the study region. 5Synthesis and applications. Under current legislation in Canada, the critical habitat of woodland caribou must be defined, and then protected. Our autoregressive models can help to identify landscapes to prioritize conservation efforts. The probability of occurrence of caribou was related to different landscape characteristics across their range, which implies that the typical habitat of woodland caribou differs spatially. Such behavioural plasticity could be problematic for defining critical habitat, but we showed that spatial variation in landscape selection was organized along geographical gradients. Our study illustrates how geographical trends in habitat selection can guide management and conservation decisions. [source] Genetic, physiologic and ecogeographic factors contributing to variation in Homo sapiens: Homo floresiensis reconsideredJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 6 2006GARY D. RICHARDS Abstract A new species, Homo floresiensis, was recently named for Pleistocene hominid remains on Flores, Indonesia. Significant controversy has arisen regarding this species. To address controversial issues and refocus investigations, I examine the affinities of these remains with Homo sapiens. Clarification of problematic issues is sought through an integration of genetic and physiological data on brain ontogeny and evolution. Clarification of the taxonomic value of various ,primitive' traits is possible given these data. Based on this evidence and using a H. sapiens morphological template, models are developed to account for the combination of features displayed in the Flores fossils. Given this overview, I find substantial support for the hypothesis that the remains represent a variant of H. sapiens possessing a combined growth hormone,insulin-like growth factor I axis modification and mutation of the MCPH gene family. Further work will be required to determine the extent to which this variant characterized the population. [source] Defending the Scientific Foundations of the Firearms and Tool Mark Identification Discipline: Responding to Recent ChallengesJOURNAL OF FORENSIC SCIENCES, Issue 3 2007Ronald G. Nichols M.Ch.M. ABSTRACT: Recent challenges have brought the discipline of firearms and tool mark identification to the forefront in recent court cases. This article reviews those challenges and offers substantial support for the scientific foundations of the firearms and tool mark identification discipline. A careful review of the available literature has revealed that firearms and tool mark identification is rooted in firm scientific foundations, critically studied according to the precepts of the scientific method culminating in the Association of Firearms and Toolmark Examiners' Theory of Identification. Firearms and tool mark identification has been validated in a manner appropriate for evidence of the kind to be expected in firearms and tool mark examinations. Proficiency tests and error rates have been studied and can provide consumers of the disciple with a useful guide as to the frequency with which misidentifications are reported in the community using appropriate methodologies and controls. As a result, the primary issues in recent challenges do not invalidate the firearms and tool mark discipline as a science nor should it detract it from its admissibility in a court of law. [source] The Impact of Underage Drinking Laws on Alcohol-Related Fatal Crashes of Young DriversALCOHOLISM, Issue 7 2009James C. Fell Background:, This study used a pre- to post-design to evaluate the influence on drinking-and-driving fatal crashes of 6 laws directed at youth aged 20 and younger and 4 laws targeting all drivers. Methods:, Data on the laws were drawn from the Alcohol Policy Information System data set (1998 to 2005), the Digests of State Alcohol Highway Safety Related Legislation (1983 to 2006), and the Westlaw database. The Fatality Analysis Reporting System data set (1982 to 2004) was used to assess the ratio of drinking to nondrinking drivers involved in fatal crashes [fatal crash incidence ratio (CIR)]. The data were analyzed using structural equation modeling techniques. Results:, Significant decreases in the underage fatal CIR were associated with presence of 4 of the laws targeting youth (possession, purchase, use and lose, and zero tolerance) and 3 of the laws targeting all drivers (0.08 blood alcohol concentration illegal per se law, secondary or upgrade to a primary seat belt law, and an administrative license revocation law). Beer consumption was associated with a significant increase in the underage fatal CIR. The direct effects of laws targeting drivers of all ages on adult drinking drivers aged 26 and older were similar but of a smaller magnitude compared to the findings for those aged 20 and younger. It is estimated that the 2 core underage drinking laws (purchase and possession) and the zero tolerance law are currently saving an estimated 732 lives per year controlling for other exposure factors. If all states adopted use and lose laws, an additional 165 lives could be saved annually. Conclusions:, These results provide substantial support for the effectiveness of under age 21 drinking laws with 4 of the 6 laws examined having significant associations with reductions in underage drinking-and-driving fatal crashes. These findings point to the importance of key underage drinking and traffic safety laws in efforts to reduce underage drinking-driver crashes. [source] "BACK THE BID": THE 2012 SUMMER OLYMPICS AND THE GOVERNANCE OF LONDONJOURNAL OF URBAN AFFAIRS, Issue 3 2007PETER NEWMAN ABSTRACT:,The Olympic Park being developed in east London for the 2012 Games is one large urban renewal project among many in the city. The impact of the Games on urban development may be of less significance than the impact on city politics. Bidding for and delivering the Games has contributed to a reassessment of the recent experiment with mayoral government. The article examines these changing representations of the structures of London government that are now seen as a success. Much of the literature on Olympic cities is highly critical of the impact of the games, but the (current) substantial support for London 2012 also needs to be explained. We examine how London has created opportunities for support, and moments and spaces for celebration when political leaders and Londoners can come together around particular representations of themselves and the city. [source] A phylogeny of anisopterous dragonflies (Insecta, Odonata) using mtRNA genes and mixed nucleotide/doublet modelsJOURNAL OF ZOOLOGICAL SYSTEMATICS AND EVOLUTIONARY RESEARCH, Issue 4 2008G. Fleck Abstract The application of mixed nucleotide/doublet substitution models has recently received attention in RNA-based phylogenetics. Within a Bayesian approach, it was shown that mixed models outperformed analyses relying on simple nucleotide models. We analysed an mt RNA data set of dragonflies representing all major lineages of Anisoptera plus outgroups, using a mixed model in a Bayesian and parsimony (MP) approach. We used a published mt 16S rRNA secondary consensus structure model and inferred consensus models for the mt 12S rRNA and tRNA valine. Secondary structure information was used to set data partitions for paired and unpaired sites on which doublet or nucleotide models were applied, respectively. Several different doublet models are currently available of which we chose the most appropriate one by a Bayes factor test. The MP reconstructions relied on recoded data for paired sites in order to account for character covariance and an application of the ratchet strategy to find most parsimonious trees. Bayesian and parsimony reconstructions are partly differently resolved, indicating sensitivity of the reconstructions to model specification. Our analyses depict a tree in which the damselfly family Lestidae is sister group to a monophyletic clade Epiophlebia + Anisoptera, contradicting recent morphological and molecular work. In Bayesian analyses, we found a deep split between Libelluloidea and a clade ,Aeshnoidea' within Anisoptera largely congruent with Tillyard's early ideas of anisopteran evolution, which had been based on evidently plesiomorphic character states. However, parsimony analysis did not support a clade ,Aeshnoidea', but instead, placed Gomphidae as sister taxon to Libelluloidea. Monophyly of Libelluloidea is only modestly supported, and many inter-family relationships within Libelluloidea do not receive substantial support in Bayesian and parsimony analyses. We checked whether high Bayesian node support was inflated owing to either: (i) wrong secondary consensus structures; (ii) under-sampling of the MCMC process, thereby missing other local maxima; or (iii) unrealistic prior assumptions on topologies or branch lengths. We found that different consensus structure models exert strong influence on the reconstruction, which demonstrates the importance of taxon-specific realistic secondary structure models in RNA phylogenetics. [source] Helioseismic analysis of the solar flare-induced sunquake of 2005 January 15MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 3 2007H. Moradi ABSTRACT We report the discovery of one of the most powerful sunquakes detected to date, produced by an X1.2-class solar flare in active region AR10720 on 2005 January 15. We used helioseismic holography to image the source of seismic waves emitted into the solar interior from the site of the flare. Acoustic egression power maps at 3 and 6 mHz with a 2-mHz bandpass reveal a compact acoustic source strongly correlated with impulsive hard X-ray and visible-continuum emission along the penumbral neutral line separating the two major opposing umbrae in the ,-configuration sunspot that predominates AR10720. At 6 mHz the seismic source has two components, an intense, compact kernel located on the penumbral neutral line of the ,-configuration sunspot that predominates AR10720, and a significantly more diffuse signature distributed along the neutral line up to ,15 Mm east and ,30 Mm west of the kernel. The acoustic emission signatures were directly aligned with both hard X-ray and visible continuum emission that emanated during the flare. The visible continuum emission is estimated at 2.0 × 1023 J, approximately 500 times the seismic emission of ,4 × 1020 J. The flare of 2005 January 15 exhibits the same close spatial alignment between the sources of the seismic emission and impulsive visible continuum emission as previous flares, reinforcing the hypothesis that the acoustic emission may be driven by heating of the low photosphere. However, it is a major exception in that there was no signature to indicate the inclusion of protons in the particle beams thought to supply the energy radiated by the flare. The continued strong coincidence between the sources of seismic emission and impulsive visible continuum emission in the case of a proton-deficient white-lightflare lends substantial support to the ,back-warming' hypothesis, that the low photosphere is significantly heated by intense Balmer and Paschen continuum-edge radiation from the overlying chromosphere in white-light flares. [source] What Presidents Talk about: The Nixon CasePRESIDENTIAL STUDIES QUARTERLY, Issue 4 2003Lawrence R. Jacobs Aside from the much-analyzed State of the Union addresses and other major speeches, existing research tells us little about which issues presidents emphasize in their public rhetoric, how they do it, why, and with what effects. This article closely analyzes the public rhetoric of Richard Nixon over his entire presidency. The first section catalogs key characteristics of Nixon's rhetoric that confirm central expectations of the modern "public presidency" including the tendency of the "rhetorical presidency" toward oral rather than written formats, the orientation of "going public" by primarily addressing the general public rather than elite audiences, and a "two-presidency" tilt toward emphasizing foreign over domestic policy. In addition, the article uses the month-to-month variations in the amount and content of presidential rhetoric to examine two hypotheses,that presidential rhetoric is a strategic tool that presidents use to affect real-world events (rhetoric-driven events) and that rhetoric is cast about by the winds of the world (event-driven rhetoric). Despite the impression in some presidential studies that presidents are primarily movers of events, our findings offer substantial support for the event-driven rhetoric hypothesis and only some evidence of the rhetoric-driven event hypothesis. [source] Product involvement in organic food consumption: Does ideology meet practice?PSYCHOLOGY & MARKETING, Issue 9 2009Anssi Tarkiainen This study assesses the level of consumers' felt involvement in four distinct product categories of organic food (coffee, bread, fruit, and flour), and examines the role of felt involvement in the broader context of organic food shopping behavior. It is shown that the reason why consumers do not buy organic food regularly despite their positive attitudes is that such ideologically formed attitudes are not present in habitual, low-involvement shopping activities with limited problem-solving needs as in food shopping from grocery stores. The statistical analysis of an empirical sample of 200 consumers gives substantial support to the hypothesized new organic food buying behavior model. © 2009 Wiley Periodicals, Inc. [source] Perceived Environmental Uncertainty, Entry Mode Choice and Satisfaction with EC-MNC PerformanceBRITISH JOURNAL OF MANAGEMENT, Issue 3 2000Lance Eliot Brouthers Previous theoretical and empirical research provides substantial support for a contingency approach toward international entry-mode selection. Similarly, additional empirical research supports the notion that different international ownership-based entry modes tend to be associated with varying performance levels. In this study we provide an initial attempt to use Werner, Brouthers and Brouthers' (1996) multiple measures of Perceived Environmental Uncertainty (PEU) to determine the entry mode choices of firms and link these risk-adjusted mode choices to managerial satisfaction with firm performance. We hypothesize and find that firms which make PEU risk-adjusted entry mode choices are significantly more satisfied with their firm's performance than firms whose entry mode choices cannot be predicted using multiple PEU risk measures. [source] | ||||||||||||||||